Hello,
I keep blowing the fuse that leads to the input of my step up transformer that leads to the solar input of my delta 2, and can't figure out why?
I have 2 independent step up transformers for testing. Separate configurations, and connected to a 12.8v 200ah LiPo4 external battery via a fused input.
The ultimate goal is to get either below boost converters to provide near 500w dc charging power to the delta 2 via the solar input port.
Xformer A = 12v to 24v 20a(max)- 20a inline fuse (delta 2 limits to 8a draw with xt60 or xt60i center pin not grounded properly.
Xformer B = 12v to 48v 10a(max)- 10a inline fuse
I have 2 solar input cables that I swap out for testing.
(On each end, there is an Orange xt60i connector with the copper center pin).
One cable has the xt60i on one end with the Elfculb MC4 connector & patch cable to transformer output. This cable's center pin is confirmed grounded to neg side of xt60i (rounded end). We will call this the 'Elfculb cable '. When using this cable it blows fuse with either transformer.
The other xt60i cable's center pin has no connection to either + or - of connector, and doesn’t blow fuse when using the 12v to 24v transformer (provides 187w charging power) but does blow fuse with the 48v up converter.
If I use the 'Elfculb cable' with either converter, the one with the xt60i center pin grounded, it blows the fuse every time.
The fuse goes from the batt + to a terminal block which then goes to the batt cutoff switch, and then to the input of the converter.
I've tested the 48v converter's output voltage, and it outputs 48.1 volts, so converter seems good.
Any idea?
Never mind. I believe I found the answer below:
Found solution:
-12v/24v 20a boost converter
-use Elfculb cable with grounded center pin- enables 15a max
-30a fuse between batt + terminal before converter input (math below)
My math:
Converter under load outputs 23.1v (not 24v)
23.1v x 15a = 346.5w dc charging of delta 2 battery via solar input port
Since battery voltage for LiPo4 can go down to 12.5v at 0% charge, we determine:
Fuse determination is: 346.5w / 12.5v = 27.72a or rounded to 30a.
Attached shows dc charging of 346w from external battery to delta 2 which is 85% increase from 187w.
In summary, use a confirmed grounded center pin xt60i connector and do the math to determine the fuse size and wire gauge to the converter input.
If I up the boost converter to 48v to increase the dc charging wattage to max or just below max of 500w, I calculate that I will need 40a fuse and 8awg wire.
Also, I used an added 12v fan to expel heat from the converter.
Disclaimer: I'm a complete novice or professional idiot. This is my very first diy project. I did use a multimeter and temperature gun, and watched many YouTube videos.
I keep blowing the fuse that leads to the input of my step up transformer that leads to the solar input of my delta 2, and can't figure out why?
I have 2 independent step up transformers for testing. Separate configurations, and connected to a 12.8v 200ah LiPo4 external battery via a fused input.
The ultimate goal is to get either below boost converters to provide near 500w dc charging power to the delta 2 via the solar input port.
Xformer A = 12v to 24v 20a(max)- 20a inline fuse (delta 2 limits to 8a draw with xt60 or xt60i center pin not grounded properly.
Xformer B = 12v to 48v 10a(max)- 10a inline fuse
I have 2 solar input cables that I swap out for testing.
(On each end, there is an Orange xt60i connector with the copper center pin).
One cable has the xt60i on one end with the Elfculb MC4 connector & patch cable to transformer output. This cable's center pin is confirmed grounded to neg side of xt60i (rounded end). We will call this the 'Elfculb cable '. When using this cable it blows fuse with either transformer.
The other xt60i cable's center pin has no connection to either + or - of connector, and doesn’t blow fuse when using the 12v to 24v transformer (provides 187w charging power) but does blow fuse with the 48v up converter.
If I use the 'Elfculb cable' with either converter, the one with the xt60i center pin grounded, it blows the fuse every time.
The fuse goes from the batt + to a terminal block which then goes to the batt cutoff switch, and then to the input of the converter.
I've tested the 48v converter's output voltage, and it outputs 48.1 volts, so converter seems good.
Any idea?
Never mind. I believe I found the answer below:
Found solution:
-12v/24v 20a boost converter
-use Elfculb cable with grounded center pin- enables 15a max
-30a fuse between batt + terminal before converter input (math below)
My math:
Converter under load outputs 23.1v (not 24v)
23.1v x 15a = 346.5w dc charging of delta 2 battery via solar input port
Since battery voltage for LiPo4 can go down to 12.5v at 0% charge, we determine:
Fuse determination is: 346.5w / 12.5v = 27.72a or rounded to 30a.
Attached shows dc charging of 346w from external battery to delta 2 which is 85% increase from 187w.
In summary, use a confirmed grounded center pin xt60i connector and do the math to determine the fuse size and wire gauge to the converter input.
If I up the boost converter to 48v to increase the dc charging wattage to max or just below max of 500w, I calculate that I will need 40a fuse and 8awg wire.
Also, I used an added 12v fan to expel heat from the converter.
Disclaimer: I'm a complete novice or professional idiot. This is my very first diy project. I did use a multimeter and temperature gun, and watched many YouTube videos.
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